According to a conventional technique shown in U.S. design Pat. D410,372 entitled “screwdriver bit”, its appearance showed that the upper section portion is a hexagon shaft where the lower section portion has a circular shaft. A protruding ring section with larger exterior diameter is formed to the upper position of the circular shaft where a cross driving portion is formed to the lower position of the circular shaft. Since the foregoing conventional technique belonged to the design patent, it may not understand that how can the protruding ring section disposed to the upper position of the circular shaft work; and further it may not understand that whether the protruding ring section is integrated with or connected to the circular shaft.
Therefore, the screwdriver bit structure having the appearance that is similar to the protruding ring section for sale on market can be approximately divided into two categories.
First, the protruding ring section is integrated with the screwdriver bit through the forging process. Afterward, the external surface of the protruding ring section is coated with colors for recognition purpose.
Second, the protruding ring section with colors is directly combined with a predetermined place of the screwdriver bit through plastic injection. The protruding ring section can closely cover the shaft of the screwdriver bit through the combination manner so as to firmly achieve the integration. Consequently, the protruding ring section cannot be rotated individually. At the most, the efficiency can merely provide recognition purpose.
Upon the foregoing technique, no matter which technique is used to complete U.S. design Pat. D410,372, the protruding ring section is integrated with the screwdriver bit through consolidation to achieve the color recognition function and the protruding ring section may not perform independent rotation by itself as well.
Accordingly, to overcome the foregoing shortcomings, the inventor(s) of the present invention based on years of experience in the related field to conduct extensive researches and experiments for the screwdriver structure with the auxiliary sheath, and finally invented a screwdriver bit structure having auxiliary positioning function.